/**
* Double the bit width.
*
* This will only change the number of bits the values are represented, not the
* values themselves.
*/
void
lp_build_unpack2(struct gallivm_state *gallivm,
struct lp_type src_type,
struct lp_type dst_type,
LLVMValueRef src,
LLVMValueRef *dst_lo,
LLVMValueRef *dst_hi)
{
LLVMBuilderRef builder = gallivm->builder;
LLVMValueRef msb;
LLVMTypeRef dst_vec_type;
assert(!src_type.floating);
assert(!dst_type.floating);
assert(dst_type.width == src_type.width * 2);
assert(dst_type.length * 2 == src_type.length);
if(dst_type.sign && src_type.sign) {
/* Replicate the sign bit in the most significant bits */
msb = LLVMBuildAShr(builder, src, lp_build_const_int_vec(gallivm, src_type, src_type.width - 1), "");
}
else
/* Most significant bits always zero */
msb = lp_build_zero(gallivm, src_type);
/* Interleave bits */
#ifdef PIPE_ARCH_LITTLE_ENDIAN
*dst_lo = lp_build_interleave2(gallivm, src_type, src, msb, 0);
*dst_hi = lp_build_interleave2(gallivm, src_type, src, msb, 1);
#else
*dst_lo = lp_build_interleave2(gallivm, src_type, msb, src, 0);
*dst_hi = lp_build_interleave2(gallivm, src_type, msb, src, 1);
#endif
/* Cast the result into the new type (twice as wide) */
dst_vec_type = lp_build_vec_type(gallivm, dst_type);
*dst_lo = LLVMBuildBitCast(builder, *dst_lo, dst_vec_type, "");
*dst_hi = LLVMBuildBitCast(builder, *dst_hi, dst_vec_type, "");
}
/**
* Convert linear float soa values to packed srgb AoS values.
* This only handles packed formats which are 4x8bit in size
* (rgba and rgbx plus swizzles), and 16bit 565-style formats
* with no alpha. (In the latter case the return values won't be
* fully packed, it will look like r5g6b5x16r5g6b5x16...)
*
* @param src float SoA (vector) values to convert.
*/
LLVMValueRef
lp_build_float_to_srgb_packed(struct gallivm_state *gallivm,
const struct util_format_description *dst_fmt,
struct lp_type src_type,
LLVMValueRef *src)
{
LLVMBuilderRef builder = gallivm->builder;
unsigned chan;
struct lp_build_context f32_bld;
struct lp_type int32_type = lp_int_type(src_type);
LLVMValueRef tmpsrgb[4], alpha, dst;
lp_build_context_init(&f32_bld, gallivm, src_type);
/* rgb is subject to linear->srgb conversion, alpha is not */
for (chan = 0; chan < 3; chan++) {
unsigned chan_bits = dst_fmt->channel[dst_fmt->swizzle[chan]].size;
tmpsrgb[chan] = lp_build_linear_to_srgb(gallivm, src_type, chan_bits, src[chan]);
}
/*
* can't use lp_build_conv since we want to keep values as 32bit
* here so we can interleave with rgb to go from SoA->AoS.
*/
alpha = lp_build_clamp_zero_one_nanzero(&f32_bld, src[3]);
alpha = lp_build_mul(&f32_bld, alpha,
lp_build_const_vec(gallivm, src_type, 255.0f));
tmpsrgb[3] = lp_build_iround(&f32_bld, alpha);
dst = lp_build_zero(gallivm, int32_type);
for (chan = 0; chan < dst_fmt->nr_channels; chan++) {
if (dst_fmt->swizzle[chan] <= PIPE_SWIZZLE_W) {
unsigned ls;
LLVMValueRef shifted, shift_val;
ls = dst_fmt->channel[dst_fmt->swizzle[chan]].shift;
shift_val = lp_build_const_int_vec(gallivm, int32_type, ls);
shifted = LLVMBuildShl(builder, tmpsrgb[chan], shift_val, "");
dst = LLVMBuildOr(builder, dst, shifted, "");
}
}
return dst;
}